OF WASHINGTON. 315 



the mandibles are clothed with stiff, reddish bristles; the legs and palpi 

 are of the usual shape, and clothed with moderately short hairs and some 

 spines; the triangular piece at base of venter has a depressed area on its 

 posterior part, broadest behind, and its margin each side terminated by a 

 deep indentation. 



One specimen, Los Angeles, California [Davidson]. It is 

 easily distinguished by the serrate appearance of the lower finger 

 [which does not occur in any other species], and by the coloring 

 of the palpi. 



Discussion followed by Messrs. Ashmead, Banks, and Marlatt 

 relating more particularly to structural characteristics commented 

 on by the author of the paper, and particularly the value of the man- 

 dibular teeth of insects in classification, Mr. Ashmead speaking of 

 the use of this characteristic in the classification of ants by old au 

 thorities ; and the modification or wear of the teeth in old speci 

 mens was also noted and the important modification which wear 

 sometimes effects in the case of cicada larvae two or three years 

 after moulting was described by Mr. Marlatt. 



The third paper was by Mr. Dyar, and was entitled : 



DESCRIPTIONS OF THE LARVAE OF FIFTY NORTH AMER 

 ICAN NOCTUID^E. 



By HARRISON G. DYAR. 



The Noctuid larvae here described are from the collection of the 

 U. S. National Museum, and are those of which descriptions 

 have not been previously published to my knowledge. 



Unless otherwise stated, the head is rounded, almost as high 

 as wide, moderately bilobed, the clypeus reaching about half way 

 to the vertex ; slightly retracted below joint 2. Cervical shield 

 indistinct, not cornified. Body cylindrical, abdominal feet equally 

 developed on joints 7 to 10 and 13 ; joint 12 not, or but slightly, 

 enlarged. Tubercles normal, single, iv behind the spiracle, 

 about equally distant from iii and v or nearer to iii than to v. 

 The longitudinal lines are the dorsal, situated centrally on the 

 back, unpaired ; the subdorsal, half way between the dorsal and 

 the spiracles, paired ; the lateral, halfway between the subdorsal 

 and the spiracles, not touching the latter ; the suprastigmatal or 

 stigmatal, just touching the tops of the spiracles or partly enclos 

 ing them and occupying all the space between the lateral and 

 substigmatal lines; the substigmatal running below the spiracles 

 and enclosing their lower portion. The ordinary lines are the 



